annotate tests/failfilemerge.py @ 44261:04a3ae7aba14

chg: force-set LC_CTYPE on server start to actual value from the environment

Python 3.7+ will "coerce" the LC_CTYPE variable in many instances, and this can
cause issues with chg being able to start up. D7550 attempted to fix this, but a
combination of a misreading of the way that python3.7 does the coercion and an
untested state (LC_CTYPE being set to an invalid value) meant that this was
still not quite working.

This change will cause differences between chg and hg: hg will have the LC_CTYPE
environment variable coerced, while chg will not. This is unlikely to cause any
detectable behavior differences in what Mercurial itself outputs, but it does
have two known effects:

-   When using hg, the coerced LC_CTYPE will be passed to subprocesses, even
    non-python ones. Using chg will remove the coercion, and this will not
    happen. This is arguably more correct behavior on chg's part.
-   On macOS, if you set your region to Brazil but your language to English,
    this isn't representable in locale strings, so macOS sets LC_CTYPE=UTF-8. If
    this value is passed along when ssh'ing to a non-macOS machine, some
    functions (such as locale.setlocale()) may raise an exception due to an
    unsupported locale setting. This is most easily encountered when doing an
    interactive commit/split/etc. when using ui.interface=curses.

Differential Revision: https://phab.mercurial-scm.org/D8039

# extension to emulate interrupting filemerge._filemerge

from __future__ import absolute_import

from mercurial import (
    error,
    extensions,
    filemerge,
)


def failfilemerge(
    filemergefn, premerge, repo, wctx, mynode, orig, fcd, fco, fca, labels=None
):
    raise error.Abort("^C")
    return filemergefn(premerge, repo, mynode, orig, fcd, fco, fca, labels)


def extsetup(ui):
    extensions.wrapfunction(filemerge, '_filemerge', failfilemerge)